The present invention relates generally to a vehicle hood that is deployable upwardly in response to the vehicle impacting a pedestrian to provide additional crush space between the hood and underhood components.
In modern automotive design it is desirable for visibility, aerodynamic and styling reasons that the hood line be kept as low as possible. As a result, there is generally very little clearance between the hood and the engine bay contents of the automotive vehicle. As a result, the hood is unable to yield enough to provide significant cushioning when a pedestrian strikes the hood during an accident. Pedestrian safety performance can be improved by increasing the clearance between the hood and the vehicle components beneath the hood.
One way to achieve a greater clearance while maintaining a low hood line during normal vehicle operations is to provide a device to raise the hood in response to or immediately prior to the vehicle impacting a pedestrian.
Systems have been proposed for raising a vehicle hood using an actuating cylinder/piston with its line of action oriented vertically and acting on the hood to urge it upward when activated. Examples of such systems are disclosed in U.S. Pat. Nos. 6,217,108 and 6,182,782.
The present invention provides a pedestrian safety device for an automotive vehicle having a body structure with an upper surface and a hood with a trailing edge and a leading edge. The safety device comprises a hinge arm having a pivot end rotatably connected to the hood adjacent the trailing edge and a sliding end restrained for movement along a path generally parallel with the upper surface of the body structure. The hinge arm is movable between a normal operating position wherein the slide end is adjacent the forward end of the path and the pivot end is relatively close to the upper surface of the vehicle body structure, and a raised position wherein the slide end is adjacent the rear end of the path and the pivot end is raised with respect to the normal position, movement of the hinge arm from the normal position to the raised position causing the trailing edge of the hood to move upwardly. An actuator is disposed on the body structure and engages the hinge arm, acting along a line of action generally parallel with the path. The actuator has a retracted condition wherein the hinge arm is in the normal operating position and is movable to an extended condition to urge the hinge arm to the raised position. Movement of the hinge arm to the raised position results in the trailing edge of the hood being lifted upward, thus creating a greater amount of crush space between the hood and underhood components so that the hood may absorb more kinetic energy when struck by a pedestrian. The alignment of the actuator and path generally parallel with the upper surface of the vehicle structure permits the actuator to be mounted on or near the top of the body structure immediately beneath the hood, thus reducing the cost and complexity of installation and repair of the actuator.
According to another feature of the invention, the pedestrian safety device further comprises a pivot structure connecting the body structure with the hood adjacent the leading edge and providing a lateral axis about which the hood rotates relative to the body structure when the hinge arm moves to the raised position. The pivot structure preferably is part of a latch mechanism used to alternatively secure the hood closed and permit the hood to be opened during normal operation. The pivot structure also preferably enables the hood leading edge to translate rearward when the trailing edge of the hood moves upwardly. This rearward translation ensures that the hood leading edge does not impinge on other portions of the vehicle structure during deployment, such as the headlamp or grille.
According to another feature of the invention, the pivot end of the hinge arm is connected to the hood by a pivot mechanism about which the hood rotates for normal opening and closing of the hood when the hinge arm is in the normal operating position. The pivot end of the hinge arm is engaged by a retaining member disposed on the vehicle structure when in the normal operating position and is retained in a proper location for opening and closing of the hood. The retaining member preferably comprises a slot that has an open end facing upward to direct the pivot end to move upward when moving to the raised position and to prevent the hood trailing edge from being raised when the actuator is in the retracted condition. The invention device thus provides a simple, compact hinge mechanism that allows the hood to function normally prior to deployment of the hood.
According to another feature of the invention, the actuator pivotingly is connected to the body structure so that it may rotate as necessary to maintain an optimum alignment with the hinge arm during upward deployment of the hood.
Other features and advantages of the present invention will be readily appreciated and better understood after reading the subsequent description when considered in connection with the accompanying drawings.